51.   But all involved say major obstacles may be encountered before it can be proven effective in people.

52.   But before getting started, he said, one must clear a major obstacle, determining who is responsible.

53.   But Efrat and other settlements in the West Bank also are a symbol of Jewish hegemony to Palestinians and a major obstacle in the stalled Middle East peace process.

54.   But company officials and analysts do not expect the proposed merger to face major regulatory obstacles.

55.   But doubts about Congo President Kabila remain a major obstacle.

56.   But it must overcome some major obstacles.

57.   But health-care analysts say that the new venture faces major obstacles that are purely a result of the marketplace.

58.   But the anti-shutdown provision proved a major obstacle.

59.   But the major obstacles, keeping up with technology and access to capital, are more problematic for black and hispanic women than whites.

60.   But the major obstacle came from Sen. Connie Mack, R-Fla., a member of the Banking Committee and chairman of the Congressional Joint Economic Committee.